Nazarenko Sergey, Quinn Brenda
Mathematics Institute, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom.
Phys Rev Lett. 2009 Sep 11;103(11):118501. doi: 10.1103/PhysRevLett.103.118501.
We study quasigeostrophic (QG) and plasma drift turbulence within the Charney-Hasegawa-Mima (CHM) model. We focus on the zonostrophy, an extra invariant in the CHM model, and on its role in the formation of zonal jets. We use a generalized Fjørtoft argument for the energy, enstrophy, and zonostrophy and show that they cascade anisotropically into nonintersecting sectors in k space with the energy cascading towards large zonal scales. Using direct numerical simulations of the CHM equation, we show that zonostrophy is well conserved, and the three invariants cascade as predicted by the Fjørtoft argument.
我们在Charney-Hasegawa-Mima（CHM）模型中研究准地转（QG）和等离子体漂移湍流。我们关注纬向非平衡，它是CHM模型中的一个额外不变量，以及它在纬向急流形成中的作用。我们对能量、位涡量和纬向非平衡使用广义的Fjørtoft论证，并表明它们在k空间中各向异性地级联到不相交的扇区，能量级联向大的纬向尺度。通过对CHM方程的直接数值模拟，我们表明纬向非平衡得到了很好的守恒，并且这三个不变量如Fjørtoft论证所预测的那样级联。
